The present invention relates to a process for the removal of xanthines from cocoa beans.
In recent years, the need has arisen to remove xanthines such as caffeine and theobromine from cocoa beans for the production of consumer products prepared from cocoa beans, owing to their undesirable stimulant and diuretic properties. The differences in physico-chemical properties between caffeine and theobromine make the separation of these two compounds from cocoa beans relatively complex. For instance, typical concentration levels of theobromine in cocoa beans vary from 5 to 13 times greater than that of caffeine and, in terms of solubility in water, theobromine requires 40 times more water than caffeine. Consequently, an economical process to remove both the caffeine and theobromine is more difficult than the removal of caffeine alone from cocoa beans.
Conventional processes for the liquid leaching of cocoa beans with water as the leaching fluid using mechanical agitation can remove in excess of 97% xanthines provided that the contact time between the cocoa solids and the leachant is sufficient, usually at least 2 hours. However, the handling and processing of the slurry produced as a result of the leaching pose severe processing problems (e.g., the separation of feedstock and extract, xanthine removal from the extract, etc.).
French patent No. 2459001 describes a process for decaffeinating coffee beans in which the coffee beans are suspended in a liquid and the suspension is irradiated by ultrasonics of frequency in the range of 13 to 100 kHz with sufficient energy to cause cavitation. However, the maximum decaffeination level disclosed is only 80% and there is no mention of cocoa or theobromine.